The Rare Earths: Their Occurrence, Chemistry, and Technology

by Stanley Isaac Levy

Monoclinic; prismatic or tabular habit.

G = 3·41-3·44. H = = 5¹⁄₂-6. Light yellow; pleochroic.

Langesund Fiord.

Xenotime.

Phosphate of E, with ThO₂, SiO₂, Zr, etc. Cer = 0-11; Yttr = 54·1-64·7; ThO₂ = 1-5%.

Tetragonal; isomorphous with Zircon?

G = 4·45-4·56. H = 4-5. Brown to yellow; opaque.

Diamond sands of Brazil; Norway.

Yttrialite (Green Gadolinite).

A weathered [gadolinite] (q.v.)—E₂O₃,2SiO₂. Cer = 6·6-8·2; Yttr = 43·4-46·5; ThO₂ = 10·8-12·8%.